OBJECTIVES: Magnetic resonance imaging (MRI) has been proposed as a radiation-free alternative to high resolution computed tomography (HRCT) for the assessment and follow-up of chest disorders. Thus far, no study has compared the efficacy of high-field MRI and HRCT in children and adults with noncystic fibrosis (CF) chronic lung disease. The aims of our study were: (1) to assess whether chest high-field MRI is as effective as chest HRCT in identifying pulmonary abnormalities; and (2) to investigate the relationships between the severity and extent of lung disease, and functional data in patients with non-CF chronic lung disease. MATERIALS AND METHODS: Forty-one subjects (median age, 13.8 years; range, 5.9-29.3 years; 30 children/11 adults) with primary ciliary dyskinesia (n = 14), primary immunodeficiency (n = 14), or recurrent pneumonia (n = 13) underwent pulmonary function tests, chest HRCT (120 kV, dose-modulated mAs) and high-field 3.0-T MRI (HASTE; transversal orientation; repetition time/echo time/flip angle/acquisition time, infinite/92 milliseconds/150 degrees/approximately 90 seconds). HRCT and MRI images were scored in consensus by 2 raters using a modified version of the Helbich scoring system. The maximal score was 25. RESULTS: HRCT and high-field MRI total scores were 11 (range: 1-20) and 11 (range: 1-17), respectively. There was good agreement between the 2 techniques for all scores (r > 0.8). HRCT and MRI total scores, and extent of bronchiectasis scores were significantly related to pulmonary function tests (r = -0.4, P < 0.05). The MRI mucous plugging score was significantly related to pulmonary function tests (r = -0.4, P < 0.05). CONCLUSIONS: Chest high-field 3.0-T MRI appears to be as effective as HRCT in assessing the extent and severity of lung abnormalities in non-CF chronic lung diseases, and might be a reliable radiation-free option to HRCT.